A liquid crystal display device is widely used as a thin and low power consumption display device. The liquid crystal display device includes a liquid crystal panel, a gate driver, and a source driver. The liquid crystal panel includes a plurality of gate lines, a plurality of source lines, and a plurality of pixel circuits. The gate line, the source line, the gate driver, and the source driver are also called, for example, a scanning line, a data line, a scanning line drive circuit, and a data line drive circuit, respectively.
As a size of the liquid crystal panel becomes larger, the source line becomes longer. When the source line becomes long, a drive capability of the source driver becomes insufficient and it becomes difficult to drive the source line within a predetermined time. This problem can be solved, for example, by a method in which the drive capability of the source driver is increased. However, when this method is used, cost and power consumption of the source driver are increased. Therefore, in a liquid crystal display device having a large-sized liquid crystal panel, a method in which the source drivers are provided at both ends of the source lines and the source lines are driven from the both ends is used in some cases.
Related to the present invention, Patent Document 1 discloses a backlight device for a liquid crystal panel, the device having a tube voltage control circuit including a plurality of rectifier circuits connected in series and a plurality of MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), in which an output terminal of each rectifier circuit is connected to a control terminal of each MOSFET, in order to detect abnormality of a plurality of lamps. Patent Document 2 discloses an energizing abnormality warning system for a car lamp, the system detecting a lamp in which an energization abnormality occurs based on a change in current flowing through the lamp and displaying information about the detected lamp on a display device of a car audio system. Patent Document 3 discloses providing a standby power display means for displaying a standby power of an electric device to an overcurrent warning device which detects a current flowing through a power line, displays an energization state, and issues an alarm when an overcurrent flows.